NAME

       r.out.mpeg  - Converts raster map series to MPEG movie.

KEYWORDS

       raster, export, output, animation

SYNOPSIS

       r.out.mpeg
       r.out.mpeg --help
       r.out.mpeg  [-c]  view1=name[,name,...]  [view2=name[,name,...]]   [view3=name[,name,...]]
       [view4=name[,name,...]]    output=name    [quality=integer]     [--overwrite]     [--help]
       [--verbose]  [--quiet]  [--ui]

   Flags:
       -c
           Convert on the fly, uses less disk space
           Requires r.out.ppm with stdout option

       --overwrite
           Allow output files to overwrite existing files

       --help
           Print usage summary

       --verbose
           Verbose module output

       --quiet
           Quiet module output

       --ui
           Force launching GUI dialog

   Parameters:
       view1=name[,name,...] [required]
           Name of input raster map(s) for view no.1

       view2=name[,name,...]
           Name of input raster map(s) for view no.2

       view3=name[,name,...]
           Name of input raster map(s) for view no.3

       view4=name[,name,...]
           Name of input raster map(s) for view no.4

       output=name [required]
           Name for output file

       quality=integer
           Quality factor (1 = highest quality, lowest compression)
           Options: 1-5
           Default: 3

DESCRIPTION

       r.out.mpeg  is  a  tool  for  combining a series of GRASS raster maps into a single MPEG-1
       (Motion Pictures Experts Group) format  file.   MPEG-1  is  a  "lossy"  video  compression
       format,  so  the  quality of each resulting frame of the animation will be much diminished
       from the original raster image.  The resulting output file may then be viewed  using  your
       favorite  mpeg-format  viewing  program.   MPEG-2  and  MPEG-4 provide much better quality
       animations.

       The user may define up to four "views", or sub-windows, to animate simultaneously.   e.g.,
       View 1 could be rainfall, View 2 flooded areas, View 3 damage to bridges or levees, View 4
       other economic damage, all animated as a time series. A black  border  2  pixels  wide  is
       drawn  around  each view. There is an arbitrary limit of 400 files per view (400 animation
       frames).  Temporary files are created in the conversion process, so lack of  adequate  tmp
       space could also limit the number of frames you are able to convert.

       The  environment  variable  GMPEG_SIZE  is checked for a value to use as the dimension, in
       pixels, of the longest dimension of the animation image.  If GMPEG_SIZE is  not  set,  the
       animation  size  defaults  to  the  rows & columns in the current GRASS region, scaling if
       necessary to a default minimum size of 200 and maximum of 500.  These  size  defaults  are
       overridden  when using the -c flag (see below). The resolution of the current GRASS region
       is maintained, independent of image size.  Playback programs have to decode the compressed
       data  "on-the-fly",  therefore  smaller  dimensioned  animations will provide higher frame
       rates and smoother animations.

       UNIX - style wild cards may be used with the command line version in place of a raster map
       name, but wild cards must be quoted.

       A  quality  value of quality=1 will yield higher quality images, but with less compression
       (larger MPEG file size). Compression ratios will vary depending on the number of frames in
       the  animation, but an MPEG produced using quality=5 will usually be about 60% the size of
       the MPEG produced using quality=1.

Example

       r.out.mpeg view1="rain[1-9]","rain1[0-2]" view2="temp*"

       If the number of files differs for  each  view,  the  view  with  the  fewest  files  will
       determine the number of frames in the animation.

       With  -c  flag  the  module converts "on the fly", uses less disk space by using r.out.ppm
       with stdout option to convert frames as needed instead of converting  all  frames  to  ppm
       before encoding.  Only use when encoding a single view.  Use of this option also overrides
       any size defaults, using the CURRENTLY DEFINED GRASS REGION for the  output  size.  So  be
       careful to set region to a reasonable size prior to encoding.

KNOWN ISSUES

       MPEG  images must be 16-pixel aligned for successful compression, so if the rows & columns
       of the calculated image size (scaled, with borders added) are not evenly divisible by  16,
       a  few rows/columns will be cut off the bottom & right sides of the image. The MPEG format
       is optimized to recognize image MOTION, so abrupt changes from one frame to  another  will
       cause a "noisy" encoding.

NOTES

       This program requires the program mpeg_encode (aka ppmtompeg):

       MPEG-1 Video Software Encoder
       (Version 1.3; March 14, 1994)

       Lawrence A. Rowe, Kevin Gong, Ketan Patel, and Dan Wallach Computer Science Division-EECS,
       Univ. of Calif. at Berkeley

       Available from Berkeley: http://biowiki.org/BerkeleyMpegEncoder
       or as part of the netpbm package (ppmtompeg): http://netpbm.sourceforge.net

       Use of the -c flag requires the r.out.ppm GRASS module with the stdout option.

SEE ALSO

       r.out.ppm

AUTHOR

       Bill Brown, U.S. Army Construction Engineering Research Laboratories

SOURCE CODE

       Available at: r.out.mpeg source code (history)

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       © 2003-2019 GRASS Development Team, GRASS GIS 7.8.2 Reference Manual